Enables the stack to be marked as non-executable. This helps in making buffer-overflow attacks more difficult.

A Solaris system running a 64-bit kernel makes the stacks of all 64-bit applications non-executable by default. Setting this variable is necessary to make 32-bit applications non-executable on systems running 64-bit or 32-bit kernels.

Note – This variable exists on all systems running the Solaris 2.6, 7, 8, or 9 releases, but it is only effective on sun4u and sun4m architectures."